腫瘍の微小環境におけるミトコンドリア移転による免疫逃避

Hideki Ikeda^1,2, Katsushige Kawase^1,3, Tatsuya Nishi^4,5

¹Division of Cell Therapy, Chiba Cancer Center Research Institute, Chiba, Japan.

Nature

|January 22, 2025

まとめ

癌細胞は変異したミトコンドリアを免疫細胞に転送し,抗腫瘍反応を損なう. このミトコンドリア移転は,がんの免疫回避の新たなメカニズムであり,患者の予後と免疫療法の有効性に影響します.

科学分野:

免疫学
分子生物学
癌研究

背景:

腫瘍細胞は腫瘍の微小環境内の複雑なメカニズムで免疫攻撃を回避します
腫瘍浸透性リンパ球 (TIL) の代謝再プログラムとミトコンドリア機能障害は,抗腫瘍免疫を阻害する.
これらの免疫回避戦略の裏にある正確なメカニズムは,まだ完全に理解されていません.

研究の目的:

ガン細胞がT細胞による攻撃を回避するメカニズムを解明する.
癌の免疫回避におけるミトコンドリア移転の役割を調査する.
TIL のミトコンドリアDNA (mtDNA) 変異の機能的結果を決定する.

主な方法:

臨床腫瘍の分析
癌細胞とTILの間で共有されたmtDNA変異の識別
ミトコンドリアの移転とそのT細胞機能に対する影響を評価するインビトロおよびインビボ試験.

主要な成果:

共有されたmtDNA変異はTILと癌細胞で特定されました.
ミトコンドリアのmtDNA変異は癌細胞からTILに移行する.
移転したミトコンドリアは,阻害分子によるミトファギーに抵抗し,ホモプラズマの置換とT細胞機能障害を引き起こす.
TILsのmtDNA変異は効果因子機能と記憶形成を損なっており,抗腫瘍免疫を低下させます.
腫瘍組織におけるmtDNA変異は,メラノーマおよび非小細胞肺がんにおける免疫チェックポイント阻害剤に対する弱い反応を予測する.

結論:

ミトコンドリアが癌細胞からTIL細胞に移転することは免疫回避の新たなメカニズムです
獲得したmtDNA変異はTIL機能を妨害し,腫瘍の免疫脱出を促進します.
この経路は新しいがん免疫療法の開発のターゲットとなる可能性があります

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